Researchers estimate that tobacco control also resulted in the beneficiaries of these avoided early deaths having gained, on average, nearly two decades of life, said the study published in the Journal of American Medical Association (JAMA).

"January 2014 marks the 50th anniversary of the first surgeon general's report on smoking and health. The report stressed on efforts to reduce cigarette smoking and its effects on health," said Theodore R Holford of the Yale University School of Public Health in Connecticut, US.

"Those efforts by governments, voluntary organizations and the private sector in last 50 years have comprised the nation's tobacco control efforts," added Holford.

Holford and his colleagues conducted a study to model reductions in smoking-related mortality associated with implementation of tobacco control since 1964. Actual smoking-related mortality from 1964 through 2012 was compared with estimated mortality under no tobacco control.

The model estimated that a total of 17.7 million smoking-attributable deaths occurred between 1964 and 2012.Overall, an estimated reduction of eight million premature smoking-attributable deaths (or 'lives saved') were associated with tobacco control during this time period (5.3 million men and 2.7 million women), said the study.

From 1964-2012, it is estimated that overall, a gain of 157 million years of life was associated with tobacco control, 111 million for men and 46 million for women.

"This suggests that individuals who avoided a premature smoking-related death gained approximately 19.6 years of life on average (157 million years divided by 8 million lives saved)," added the authors.

For the population as a whole, life expectancy for men at age 40 years has increased by 7.8 years. Without tobacco control, the estimated increase would have been 5.5 years, concluded the study.

"Despite the success of tobacco control efforts in reducing premature deaths in the United States, smoking still remains a significant public health problem," the researchers wrote.